Silent PC Review and the SPCR Forums have been free of charge for all visitors since our launch over six years ago. They say you get what you pay for, yet despite the no-cost entry, the high quality of SPCR content has been applauded by visitors, other technology web sites, and the press. One reader appreciated how we manage SPCR "with such passion and devotion" in order to keep it "so useful and rewarding to visit".

There are substantial costs in delivering SPCR's high quality content, however, including continuous effort to maintain and improve test equipment, facilities and methodologies.

Our latest self-improvement initiatives are twofold:
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[*]To upgrade our sound level meter and test microphone for even higher precision at lower sound levels, and for complete Real Time Analysis of noise. The equipment will also allow high precision analysis of digital audio products, an area of growing interest for the SPCR community. The gear has been identified, and we're communicating with suppliers to obtain the best terms. The total cost of this new equipment will be approximately $4,000. The target mics have self-noise levels of 10-12 dBA, and the PC-based RTA package is capable of just about anything a $20,000 stand-alone B&K SLM can do, perhaps more. Our trusty B&K SLM is >30 years old and it's not getting any younger. It needs to be replaced before it dies.

[*]To build a new acoustic chamber with a noise floor below 15 dBA in order to make best use of the new SLM and RTA equipment. This will be a small hemi-anechoic chamber, built as a â€œfloating roomâ€

first of all, congrats on making it to six years! hopefully it will be many more.

i don't mean to sound negative or anything, cause i love this site... but i have an honest question...

what is the benefit of building an anechoic chamber? nobody lives in that kind of environment so if product A is 19dBA, and B is 15dBA, won't that be completely indistinguishable to 99.999% of us due to ambient noise?

Thats a whole lot of cash Mike, and I certainly appreciate SPCR and all of your wonderful reviews and information, but..... do you really need to measure as low as 15Db.

There are a fair number of noise making items that hit your typical floor of 19Db, but I for one consider anything that measures that low to be inaudable anyway.

I cant tell you how to run your site and I certainly wont try to, but spending $10,000 for better measuring equipment and somewhere to measure it sounds like a lot of money for a relativley small gain (4Db of recording and analyzing clarity).

Please try to sell me your warez, make me believe that $10,000 is worth what you are trying to achieve.

Different places have different ambient noise levels, so while something might be quite loud in a quiet home, it might seem absolutely silent in a different home. An anechoic chamber would give reliable values abstracted from ambient noise. I don't entirely understand what analysis of digital products means.

I don't think any of us know what SCPR receives in revenue from advertisements, or even if the net profit is a positive or negative value, so it's hard to know in what context these cash values are in. To me, 10000$ does seem like a lot of money to improve a reviewing process that is already the best I've seen. It's obviously not a waste of money since it would improve things, but it is a high cost.

My desire is less in perfect accuracy, and more about the variety of products and number of reviews. Maybe the new equipment would bring more credibility to SCPR so that manufacturers would send in more samples.

Also, indifferent individuals are greedy. I'd suggest raffling used parts or a givaway to donors. Could be just expert advice on donor's questions.

i don't mean to sound negative or anything, cause i love this site... but i have an honest question...

what is the benefit of building an anechoic chamber? nobody lives in that kind of environment so if product A is 19dBA, and B is 15dBA, won't that be completely indistinguishable to 99.999% of us due to ambient noise?

One huge difference is that Mike won't have to tip toe around at odd hours or save equipment sitting around for days or weeks at a time waiting for ambient noise conditions to be favorable.

I'm guessing every review you've ever read where mike lists his name on the by line and an ambient noise of 19 or 20 dBa is a living history of the times he was annoyed, frustrated, delayed by ambient noise that he couldn't control. Some percentage of the times he lists 18dBa might be the same but those won't stand out and we would have no way to tell from the readers side of those reviews in most cases.

I remember several reviews where he mentioned odd hours, wind, or rain as factors. Let me Google some quotes, there might be better ones but I got tired of searching so here they are:

http://www.silentpcreview.com/article683-page2.html wrote:

It is important to note that the room in which the power supplies are tested is almost always very quiet, typically <20 dBA, more often <18 dBA. If it is a noisy day (due to rain, wind, or lawn mowers) we wait until it's quieter to conduct any recordings. listening tests or sound measurements.

We discuss the noise levels of PC components routinely here in the SPCR forums, but rarely does anyone talk about their ambient noise levels. I recently had the opportunity to briefly borrow a highly sensitive calibrated B&K "1613" sound level meter from the University of BC's acoustics lab.

It dates back to 1978, weighs over 10 pounds, and is completely analog in design. Yet it has a dynamic range that spans over 130 dB. Its absolutely sensitivity reaches below 0 dBA -- at one point in the midband (~1kHz) we were seeing -4 dBA in the UBC anechoic chamber. Here is a picture, next to an 80mm fan and a hard drive for reference. (warning -- 164Kb picture!)

its technically difficult to quantitatively measure noise levels that are really close to ambient. but it's not really valid to say 'this fan is M dBA loud', by direct measurement, unless 'M' is at least something like ~6dBA above ambient (the 'delta' that the ambient level tends to add to the total measurement decreases as the measured object is louder, this ~6dBA above ambient is about where the contribution of ambient itself tends to have added only about 1dBA to the total measurement)

http://www.silentpcreview.com/node/1/ wrote:

I considered a move to a commercial space but quickly ruled that out when I realized there is no rentable commercial space where <20 dBA ambient is possible. Until I am prepared to build an anechoic chamber, this old house will have to do, with dear Betty's understanding.

_________________.Please put a country in your profile if you haven't already.This site is international but I'll assume you are in the US if you don't tell me otherwise.RAID levels thread http://www.silentpcreview.com/forums/viewtopic.php?p=388987

I tried my hand at making some donation links. Not sure how easy it is to change the donation amount after you click a fixed value link but I felt like trying it. Somebody should try one of them and let us know if they work. If so Mike could change the links or add a link in the referring article.

Given the effort he took to pioneer this site and the hard time we give him to keep up the standards he deserves a little more control and a little less frustration.

Everything in life is a trade off. Lets just hope he hasn't traded away all his sanity trying to appease our constant demands for better reviews...

_________________.Please put a country in your profile if you haven't already.This site is international but I'll assume you are in the US if you don't tell me otherwise.RAID levels thread http://www.silentpcreview.com/forums/viewtopic.php?p=388987

No, seriously, what you say is right on. Yes, I have the advantage of generally low ambient noise in my house & neighborhood, but this doesn't mean SPCR work can happen without paying close attention to whatever is going on outside. It often takes much longer than you would think to take some SPL measurements or record a couple of minutes of fan noise. There's lawn mowers in the summer, wind or rain or hail, scraping of snow shovels on the sidewalk, increased noise as more cars take shortcuts through residential lanes to avoid the mains traffic, increasing construction work over the years as Vancouver keeps expanding and growing, and -- most of all -- more jet planes overhead than ever before.

This last is probably the most intrusive change to impact SPCR operations, and it started 2-3 years ago when the airport (located in Richmond some 5-6 miles away as the crow flies) added a couple runways in response to much increased traffic. Before, we rarely had any planes fly overhead or close enough overhead to actually change noise levels in the neighborhood. It's been well documented that planes have to be flying pretty much directly overhead to cause serious noise issues. Well, the new runways have expanded the flight paths for both takeoff and landing, and now we're subject to near-overhead flights randomly all through the day -- and some evenings.

As dhanson865 conjectured, this often means waiting around for opportune times to make recordings or take SPL measurements. It's a pain in the A.

The anechoic chamber project I described will dramatically change all this. I suspect it could make us pretty much impervious to all but the closest lawn mowers. The 15 dBA target I mention is conservative. With a truly isolated and well constructed room-in-a-room, we might even get down to something like 10-12 dBA. Most importantly, a dog barking 4 houses away or a plane flying a mile or two overhead might not even be audible. That's the goal.

The other reality is that our B&K SLM was old when I got it, and it's not getting any younger. It needs to be replaced before it dies. The mics I'm examining have self-noise levels of 10-12 dBA, and the PC-based RTA package is capable of just about anything a $20,000 stand-alone SLM can do -- perhaps more.

All in all, these initiatives will lead to...

- better reviews
- more reviews

And I'm not sitting on my rear end waiting for the SPCR community of readers and forum members. I'm actively seeking sponsorships and support from all the companies that benefit from SPCR's existence, including the makers of the gear we seek. This was a move suggested by one of SPCR's advisers, who felt that because the service SPCR provides is so unique, readers who benefit will be willing to contribute towards the improvement of what's essentially their/our community. I am hoping she will be proven correct.

One thing I should mention: Another major upgrade has been underway for the last six months. The idea was born a couple of years ago, but it took all this time to come to fruition. This is a new PC-driven, mostly automated PSU testing rig that will dramatically decrease the number of manual hours required for each PSU test -- and slightly increase the accuracy/consistency of our results.

For a small PSU like 300W, it now takes about 3 hours to complete the testing. All of the work is manual, and it requires rigorous checking to eliminate errors. A big PSU -- say 700W -- easily takes 5-6 hours. A kw PSU? All day. The new PSU tester will reduce these times to less than half by eliminating most of the manual work. We still need to stop for recordings and noise measurements, but that will be the only manual work we'll be doing. The rest of the work will be automated.

The cost? Many hours of planning and meeting with the U of BC ee students who took this on as a project, plus the cost of all the materials -- about a grand, I think, tho the sum total has not been tabulated yet.

Thanks for the years of blissful quiet Mike. (and all the other contributers as well as the few manufactures that LISTEN to us)

As soon as Bush's "Let them eat cake"-check arrives, SPCR can have a piece of it too. I'll even put 6 candles on your slice!

Call it the 'Silence Stimulus Package' for our neighbors in the great white north.

Its not that white in Vancouver and we are pretty damn close to the border.

Sorry Mike I don't have anything to contribute, being a poor university student(I'm not powered by Mom and Dad lol, paying own tuition sucks). Been mostly a lurker than anything, but mad props and you have all the mental and spiritual support from me.

My first thought after reading this was, "Wow! That's some money!" but that was immediately followed by, "I wonder if this will increase the quantity of reviews?" I figured that the labor involved in putting these reviews together was quite extensive and you hit right on that subject. With the hopes of this coming to fruition, you can count on some money from me next month. I just bought a new monitor setup, so I want to wait for that credit card billing period to pass and be paid!

I love the site and the things you cover. My only gripe has always been that I wished you published more reviews!!! There is NO other place like this on the net, so I feel that it's in my best interest to support it. That said, count on $250 coming from me on May 5th.

To anyone who thinks they can't afford to donate anything, come on people, think small: $5 is not a lot of money! How many people visit the site? You're nearly spending that on a gallon of gas! How much do you spend on beer? Skip one trip to the store or one night of partying.

As a gesture of our appreciation, we will mail you a spiffy, laser-cut, adhesive-backed, SPCR logo tag for each US$100 contribution. (Those who have already reached this level of contribution can just email [email protected] and ask for one. Indicate when you made your contribution and under what email address and/or forum user name. Of course, a further contribution towards these projects would be most welcome.)

I'm actively seeking sponsorships and support from all the companies that benefit from SPCR's existence, including the makers of the gear we seek. This was a move suggested by one of SPCR's advisers, who felt that because the service SPCR provides is so unique, readers who benefit will be willing to contribute towards the improvement of what's essentially their/our community.

First, Mike, you're welcome for the pledge! (Don't worry, it's not an empty one either! )

Second, the above quote is RIGHT ON THE MONEY. Want some HARD evidence? Send the following FACTS to the manufacturers. I'll even provide them with receipts, if they don't believe it! Check out my blog for the HTPC build referenced below over on Missing Remote. You guys are even credited (multiple times, I think)!

That's just a LITTLE bit of money up there, racked up over the past few years! Thanks to you guys, our house has the quietest PC's around! I haven't regretted ANY of the purchases listed above. I feel I owe you guys a little bit in return and that's the least I can do.

Obviously, I've never posted here before, but have clearly been following the site for a while. I joined for the single purpose of expressing my thanks and maybe to help you guys get some additional funding!

Just a quick note to say that in the 24 hrs since the original message above was posted, 10 individual contributions have been made to [email protected] for "UPGRADE 2008", the largest amounts being $100. (Three contributors will be receiving SPCR logo tags.) Thank you very much for your support. We're on our way!

Just sent in my meager donation... good luck with the project, I use this site a lot for picking products I need for work.

I'd like to offer just a little bit of 'constructive criticism' if you don't mind...
An anechoic chamber with a 15db noise floor is difficult to achieve. One of the labs I work at has one of their more sensitive instruments inside a very expensive anechoic chamber, and it's noise floor is just about 10db depending on what's going on outside. (I'm told that's about as good as it gets for large rooms) It's needed because these machines are capable of measurements down to the atomic level, and even the slightest vibration can reek havoc on the measuring. This room is completely separated from the main building via huge rubber and steel shocks, has dense 3' thick walls lined with ~4" of *unknown* ultra-dense sound barrier, and extremely large foam cells to absorb ultra high frequency transmissions down to ultra low frequency radio signals. Definitely over-kill for measuring computer equipment, but it did help me when I had to build a sound-box to put some of our smaller equipment inside.

As far as SPCR related info, the reason I visit this site because our more humble instruments just need quiet control systems... AKA silentPCs with the right software installed on them:P What I ended up building a small sound box (4'x4'x6') that has a specific noise floor a little under 20db (I can't measure any lower than that with our current mic/preamp setup). Anyway, it was made by building the box out of 1 3/4" plywood and 1/4" vinyl sound barrier. The interior was lined with plain-old 1" closed-cell foam and then 'checker-boarded' with 4" acoustic foam wedges. Total cost was a little over $2k...

I'd be willing to bet that if you made a bigger, thicker box and used larger foam you'd have a very good sound box. Also remember, your chamber doesn't have to be universal since it will be only used for computer components, so the foam can/should be picked for properties relevant to that.

Just food for thought... good luck with the project. Hopefully the industry will take more notice of acoustic noise 'pollution.'[/u]

Please note that our target is 15 dBA -- not dB. There's little chance we could get 15 dB across the freq range... although, surprisingly, when there is no spurious outside noise, the dB level at >500Hz is extremely low -- better than 20 dB. It's the traffic noise 2 blocks away that adds to the <200Hz rumble which we usually don;t hear but the mics pick up. The good thing is that it seems entirely airborne, so there's no need to treat the floor, which is just underlay + carpet over a concrete/cement slab foundation.

A bit more details on the acoustic chamber --

The basic concept is much like the box you mention, but the final internal dimensions will be about 11x9x7.5' That's before any damping wedges are applied. The walls and ceiling will be standard 16"/24" spaced 3.5" steel stud construction. Interior batting will be something like Roxul safnsound and both sides of the wall will be covered with QuietRock, which basically has 8x the sound blocking capability of drywall. (It costs about that much more too.. but the savings in handling weight, and thickness more than make up for it.) The STC of the walls and ceiling will be at least 60; it may be as high as 65. Sound Transmission Class (STC) is a single-number rating of a material's or an assembly's ability to resist airborne sound transfer at the frequencies 125-4000 Hz.

A key feature is that this new chamber will be built like a 5 sided box, and the structure will touch only the floor -- there will be a 4~6" air gap between the walls of the existing room and this chamber. So there can be no transfer of vibrational energy from the house except through the air gap or up through the concrete floor. As mentioned. we've never been aware of any vibration on the ground floor; it seems safe to consider this an insignificant path for noise. Still, the walls will sit atop a resilient rubber-like "gasket". If floor-borne vibrational noise turns out to be a problem it will not be difficult to build a new floating floor to eliminate it.

The chamber will have a solid core door, and the existing door to the current room will also be replaced with a solid core door. Care will be taken to seal all gaps in the walls, ceilings and around the double-doors.

As mentioned, we already have about 30 dB attenuation of noise from the outside to the target room. If the chamber can have an STC of 65, then the total attenuation from the outside would be 95 dB or better.

I cant send much right now (another self-paying student here), but every little helps. I hope you keep us updated on how its going and cant wait for all the new equipment! Finally we'll be able to see just which fans are the absolute quietest out there!

Single mics are more manageable, simpler, more consistent w/ current test methods. Both of those mics are very pricey, the former is close to $2000, the latter is $3000.... I have hat in hand at the side door of both companies, we'll see what they offer beggars.

BTW, much thanks to the half dozen others who contributed since I last mentioned this. At this rate, with additional help from the product suppliers, we just might be able to finance it and have it all up & running within schedule! So PLEASE keep the contributions flowing to [email protected]!

Have you seen this article. It has some interesting products and a friend of mine used some of these techniques to make his home studio music room (he's a professional musician) so as not to disturb anyone. It works the other way around too of course

Have you seen this article. It has some interesting products and a friend of mine used some of these techniques to make his home studio music room (he's a professional musician) so as not to disturb anyone. It works the other way around too of course

No I haven't, but I've read about all the approaches covered there. I think the combination of our isolated room-in-room design, concrete floor, and the use of QuietRock drywall-replacement already puts us way ahead of any soundproofing in an apartment. We're starting with a more insulated space to begin with -- this is a gound floor room with a concrete floor in a house.

I tried my hand at making some donation links. Not sure how easy it is to change the donation amount after you click a fixed value link but I felt like trying it. Somebody should try one of them and let us know if they work.

yup, worked for me.
it's a good idea, i think they should go in the article

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